Worked on a US-based fintech and credit card platform, developing backend services using Python, Flask, Django, and FastAPI. Worked on REST APIs for payments, cards, users, and transactions, including ACH payments, bank transfers, refunds, settlements, and reconciliation. Integrated third-party services for bank linking, KYC, payments, notifications, and card management. Used AWS services such as Lambda, SQS, SNS, S3, SES, and CloudWatch, along with PostgreSQL, MySQL, Redshift, Redis, and SQLAlchemy. Also handled API performance, database optimization, production issues, and led a team of 8 developers.